I'm replacing my engine cooling temp (ECT) sensor. The fellow before me put some type of grease in the hole where it goes (port side of head). This grease isn't described in my shop manual. Nor is it called for. Does anyone know what this grease is?

what color
might be 2-4-C

no need for it

2 people have said "no need for it". I think I can run a continuity test on it with my electronics gauge to determine if it's dielectric grease; if so, I'll definately take it out. If not it possibly just fills the void so water doesn't sit in the hole and start rusting things. Thanks for your help.